1. Field of the Invention
The invention relates to an alloy consisting of at least three components A, B, C, which form at least a first matrix and a soft phase dispersed therein, with a first surface and a second surface disposed on top of it, the proportions of components A, B, C in the regions of the first and second surfaces being different from one another, an overlay formed therefrom, a composite material consisting of at least two different layers, a method of producing the overlay by depositing the components on a substrate whereby the quantity of the individual components deposited is adjusted by controlling the deposition input put power, as well as the use of the alloy.
2. The Prior Art
Very high demands are made of modern anti-friction bearings in terms of their capacity to withstand heat and mechanical stress, reliability and anti-friction properties. This being the case, multi-layered materials which usually have a structure comprising steel backing-bearing metal layer-running layer, optionally with intermediate layers disposed in between as diffusion barriers, have proved to be very effective because the properties required are often conflicting and single-layered bearings can only offer these to a greater or lesser degree by striking a compromise, if at all. The properties of the individual layers therefore depend on the desired application and have long been known to the person skilled in the art. Amongst other things, the running layer itself must adhere well to the bearing metal layer, must be adapted to the other bearing materials, must be capable of embedding foreign particles resulting from abrasion, exhibit a high resistance to wear and be thermally stable. However, precisely this mix of properties poses a problem because the ability to embed requires a somewhat softer material whereas, conversely, the ability to withstand wear requires a harder material.
In order to take account of these aspects, patent specification EP 0 435 980 B2, for example, proposes an axial bearing obtained by depositing a coating on a stiffening material by cathodic sputtering, in which the coating is a first material comprising the coating matrix and a soft phase of a second material dispersed therein. The content of dispersed soft phase varies continuously from a low content at the interface with the bearing material to a high content at the coating surface.